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==Demonstrates passing by reference.==

<source lang="vbnet">Module Tester
Sub Main()
Dim number1 As Integer = 2
Console.WriteLine("Before calling SquareByValue, " & "number1 is {0}", number1)
SquareByValue(number1) " passes number1 by value
Console.WriteLine("After returning from SquareByValue, " & "number1 is {0}" & vbCrLf, number1)
Dim number2 As Integer = 2
Console.WriteLine("Before calling SquareByReference, " & "number2 is {0}", number2)
SquareByReference(number2) " passes number2 by reference
Console.WriteLine("After returning from " & _
"SquareByReference, number2 is {0}" & vbCrLf, number2)
Dim number3 As Integer = 2
Console.WriteLine("Before calling SquareByReference " & "using parentheses, number3 is {0}",number3)
SquareByReference((number3)) " passes number3 by value
Console.WriteLine("After returning from " & "SquareByReference, number3 is {0}", number3)
End Sub
Sub SquareByValue(ByVal number As Integer)
Console.WriteLine("After entering SquareByValue, " & "number is {0}", number)
number *= number
Console.WriteLine("Before exiting SquareByValue, " & "number is {0}", number)
End Sub
Sub SquareByReference(ByRef number As Integer)
Console.WriteLine("After entering SquareByReference" & ", number is {0}", number)
number *= number
Console.WriteLine("Before exiting SquareByReference" & ", number is {0}", number)
End Sub
End Module</source>
<pre class=codeResult>Before calling SquareByValue, number1 is 2
After entering SquareByValue, number is 2
Before exiting SquareByValue, number is 4
After returning from SquareByValue, number1 is 2
Before calling SquareByReference, number2 is 2
After entering SquareByReference, number is 2
Before exiting SquareByReference, number is 4
After returning from SquareByReference, number2 is 4
Before calling SquareByReference using parentheses, number3 is 2
After entering SquareByReference, number is 2
Before exiting SquareByReference, number is 4
After returning from SquareByReference, number3 is 2</pre>

==Pass class by reference==

<source lang="vbnet">Option Strict On
Public Class YourClass
Private yourName As String
Private yourNumber As Decimal
Public Sub New(breed As String)
yourName = breed
End Sub
Public ReadOnly Property Name() As String
Get
Return yourName
End Get
End Property
Public Property Number() As Decimal
Get
Return yourNumber
End Get
Set
yourNumber = CDec(value)
End Set
End Property
Public Sub ShowInfo()
Console.WriteLine("This " & yourName & " weighs " & yourNumber & " pounds.")
End Sub
End Class
Public Class Tester
Public Shared Sub Main()
Dim mal As New YourClass("A")
mal.Number = 130
ChangeYourClassInfo(mal)
mal.ShowInfo
CompletelyChangeYourClassInfo(mal)
mal.ShowInfo
End Sub
Public Shared Sub ChangeYourClassInfo(ByVal aYourClass As YourClass)
aYourClass.Number = 125
End Sub
Public Shared Sub CompletelyChangeYourClassInfo(ByVal aYourClass As YourClass)
Dim newf As New YourClass("Newfoundland")
aYourClass = newf
End Sub
End Class</source>
<pre class=codeResult>This A weighs 125 pounds.
This A weighs 125 pounds.</pre>

==Pass Decimal by reference==

<source lang="vbnet">Option Strict On
Public Module Tester
Public Sub Main()
Dim salary As Decimal = 400.00d
Dim reviewPts As Integer = 12
ReceiveRaise(salary, reviewPts)
Console.WriteLine(salary)
End Sub
Function ReceiveRaise(ByRef salary As Decimal, ByVal reviewPts As Integer) _
As Boolean
Dim increasePct As Decimal
increasePct = ((reviewPts - 10) * .005d)
salary = salary * (1 + increasePct)
Return True
End Function
End Module</source>
<pre class=codeResult>404.000</pre>

==Pass value by reference==

<source lang="vbnet">Option Strict On
Imports System
Module Module1
Sub Main( )
Dim theVariable As Integer = 5
Console.WriteLine("In Run. theVariable: {0}",theVariable)
Doubler(theVariable)
Console.WriteLine("Back in Run. theVariable: {0}",theVariable)
End Sub
Public Sub Doubler(ByVal param As Integer)
Console.WriteLine("In Method1. Received param: {0}",param)
param *= 2
Console.WriteLine("Updated param. Returning new value: {0}", _
param)
End Sub

End Module</source>
<pre class=codeResult>In Run. theVariable: 5
In Method1. Received param: 5
Updated param. Returning new value: 10
Back in Run. theVariable: 5</pre>

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